The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 09, 1997
Filed:
Jan. 22, 1997
Applicant:
Inventors:
Katsumasa Harada, Yamaguchi, JP;
Masashi Shirai, Yamaguchi, JP;
Toshio Furuya, Yamaguchi, JP;
Nobuyuki Kuroda, Yamaguchi, JP;
Assignee:
Ube Industries, Ltd., Yamaguchi, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ; C07D / ; C07B / ;
U.S. Cl.
CPC ...
568763 ; 546434 ; 546436 ;
Abstract
Protocatechualdehyde is prepared by the steps of reacting piperonyl dichloride with molecular chlorine in the presence of phosphorus trichloride, phosphorus pentachloride or sulfuryl chloride to prepare dichloropiperonylidene dichloride and hydrolyzing the dichloropiperonylidene dichloride. The piperonyl dichloride can be prepared by the reaction of piperonal with thionyl chloride in the presence of dimethylformamide.